Custom Builder Functions

[mtom55]

I'd like to add some custom functions to knex which I have to use all the time but i'm finding it hard to get them to work.

They are:
knex.selectOne
knex.selectZeroOrOne

Instead of doing first, selectOne does not apply a limit and instead throws an error if it gets more than one record back. This allows the author to catch particular errors particular early.

I started with:

knex.client.QueryBuilder.prototype.selectOne = function (columns) { 
    const args = new Array(arguments.length);
    for (let i = 0; i < args.length; i++) {
      args[i] = arguments[i];
    }
    this.select.apply(this, args);
    this._method = 'first';
    //this.limit(1);
    return this;
}

but obviously the check on how many records get returned has to happen after the results have come back

Would you be able to point me in the right direction?

[tgriesser]

Just FYI This code won't work in 0.12, you'll need to require knex/lib/query/builder directly to modify that prototype.

For 1.0 I'll plan to define a standard way to customize the query builder chain like you're trying to do above, and with the addition of "hooks", you'll be able to easily setup post-result transforms.

[thetutlage]

@tgriesser I have waiting for this feature for while and start modifying the QueryBuilder prototype. It will be so great to have an interface to extend the query builder.

👍

[miketdonahue]

@tgriesser - How far are we away from 1.0?